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Featured researches published by Nektario Papa.


Interactive Cardiovascular and Thoracic Surgery | 2011

Post-implantation syndrome following endovascular abdominal aortic aneurysm repair: preliminary data

Eleni Arnaoutoglou; George Kouvelos; Haralampos J. Milionis; Anestis Mavridis; Nikolaos Kolaitis; Nektario Papa; George Papadopoulos; Miltiadis Matsagkas

OBJECTIVES Endovascular aneurysm repair (EVAR), may elicit an unexpected systemic inflammatory response, which has been named post-implantation syndrome (PIS). The aim of this study was to prospectively evaluate the association of PIS with clinical and laboratory parameters in patients who underwent EVAR for abdominal aortic aneurysms (AAA). METHODS Forty consecutive patients who underwent EVAR for AAA were studied. Complete blood count, fibrinogen, high sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-1, tumor necrosis factor-alpha were determined before and after surgery. Several parameters regarding the operation, as well as the hospitalization days were recorded. RESULTS PIS was diagnosed in 35% of the patients. Patients with PIS showed significant greater changes of inflammation marker levels, including hs-CRP and IL-6, as compared with the non-PIS group. PIS was associated with longer hospitalization. CONCLUSION PIS is a relatively common complication of EVAR used to treat AAAs and it is associated with features of a systemic inflammatory response and prolongation of hospitalization. Further studies are necessary towards understanding the underlying pathophysiology and evaluating effective preventive strategies.


Coronary Artery Disease | 2011

Postoperative levels of cardiac troponin versus CK-MB and high-sensitivity C-reactive protein for the prediction of 1-year cardiovascular outcome in patients undergoing vascular surgery

George Kouvelos; Haralampos J. Milionis; Eleni Arnaoutoglou; George Chasiotis; Constantina Gartzonika; Nektario Papa; Petros Tzimas; Miltiadis Matsagkas

ObjectiveThis study evaluated comparatively the predictive value of postoperative cardiac troponin I (cTnI), creatinine kinase (CK)-MB, and high-sensitivity C-reactive protein (hs-CRP) in 1-year cardiovascular mortality and morbidity in patients undergoing elective vascular surgery. MethodsA total of 295 consecutive patients undergoing elective noncardiac vascular surgery were prospectively followed-up over a period of 12 months. The levels of cTnI, CK-MB, and hs-CRP were measured preoperatively and 24 h after operation. The primary endpoint was the composite of cardiovascular death, nonfatal acute myocardial infarction, ischemic stroke, and unstable angina. ResultsThe primary endpoints occurred in 11 patients (3.8%). Receiver operating characteristic curve analysis showed that postoperative cTnI was a strong predictor of a cardiovascular event during 1-year follow-up (area under the curve, 0.852; P<0.001). Areas under the curve for hs-CRP and for CK-MB were 0.734 (P=0.008) and 0.494 (P=0.947). A threshold cTnI value of 0.4 ng/ml was highly associated with the occurrence of a cardiovascular event, with a sensitivity of 80% and specificity of 81%. Furthermore, cTnI levels provided a significantly better prediction than CK-MB levels (P=0.009) and tended to be superior to hs-CRP (P=0.2). ConclusionPostoperative cTnI levels seem to be superior to CK-MB and hs-CRP levels for the prediction of 1-year cardiovascular mortality and morbidity in patients undergoing elective vascular surgery.


Journal of Vascular Surgery | 2015

Standard endovascular treatment of abdominal aortic aneurysms in patients with very short proximal necks using the Endurant stent graft

Miltiadis Matsagkas; George Kouvelos; Michalis Peroulis; Stavros Avgos; Eleni Arnaoutoglou; Nektario Papa; George Papadopoulos

OBJECTIVE This study evaluated and compared the midterm results of endovascular aortic aneurysm repair with the Endurant (Medtronic Inc, Santa Rosa, Calif) stent graft system in off-label use in patients with short (<10 mm) proximal aortic necks and in patients treated according to device-specific instructions for use. METHODS This was a case-control (2:1) single-center retrospective analysis of prospectively collected data performed between September 2008 and December 2012. Analysis identified 19 elective patients with short (<10 mm) proximal necks and mild angulations (≤45°) treated with the Endurant stent graft and 38 patients matched for age, sex, and aneurysm diameter with proximal aortic necks ≥10 mm in length who met the instructions for use. End points included technical and clinical success and freedom from any secondary intervention, any type of endoleak, and aneurysm-related death. RESULTS The short-neck group was a mean ± standard deviation age of 71.7 ± 8.9 years, 84% were men, and their mean infrarenal aortic neck length was 6.1 ± 1.2 mm. Mean suprarenal and infrarenal angles were 110° ± 10.4° and 170° ± 15.4°, respectively. Aortic neck diameters were similar between the groups (26.6 ± 3.8 vs 25.7 ± 3.7 mm; P = .36). Primary technical success was achieved in all cases. Off-label patients were more likely to require additional proximal cuff deployment to successfully obtain a seal (21% vs 3%; P = .04). The two patient groups were similar in rates of perioperative mortality, morbidity, and complications. Mean follow-up of 24 ± 12 months revealed no differences in clinical success, freedom from reintervention, and aneurysm-related death. No type I endoleaks were observed in either group during the follow-up period. CONCLUSIONS The Endurant stent graft system applied off-label in patients with very short aneurysm necks (<10 mm) with mild angulation showed acceptable treatment results. These midterm results might suggest its use in carefully selected patients with very short neck anatomy. Long-term data are needed to verify the observed durability of the Endurant stent graft.


Journal of Endovascular Therapy | 2013

Analysis of Effects of Fixation Type on Renal Function After Endovascular Aneurysm Repair

George Kouvelos; Ioannis Boletis; Nektario Papa; Amalia Kallinteri; Michalis Peroulis; Miltiadis Matsagkas

Purpose To report a prospective nonrandomized study comparing the effects of suprarenal (SR) vs. infrarenal (IR) stent-graft fixation on renal function in patients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Methods Patients with AAA undergoing elective EVAR between June 2008 and June 2010 were eligible for the comparative study of fixation method on renal function. Patients with impaired renal function [estimated creatinine clearance (eCrCl) <30 mL/min] or a history of renal impairment were not eligible. Renal function was assessed by measuring serum creatinine (SCr) and total proteins and microalbumin in the urine preoperatively, on postoperative day 1, and at 1, 6, and 12 months. The eCrCl was calculated using the Cockcroft-Gault formula. A standard preoperative hydration protocol was followed in all patients, and stent-graft choice was at the operators discretion. Of 116 patients undergoing elective EVAR in the study period, 16 were ineligible, leaving 100 patients (95 men; median age 74 years) enrolled in the study (49 SR and 51 IR). Results There was no statistically significant difference between the groups in the prevalence of any risk factor, the baseline SCr and eCrCl values, contrast usage, or procedure duration. At the postoperative measurement, there was no significant deterioration of renal function in either group, although total urinary proteins increased significantly in both groups (IR p=0.01, SR p<0.001). At the 12-month follow-up, patients in the IR group had no significant alteration in any marker vs. baseline, while patients in the SR group had significant alterations in SCr (p=0.001), eCrCl (p<0.001), and microalbumin (p=0.04) in urine. The number of patients with a >20% decrease in eCrCl was not significantly different between the groups. No patient had an adverse renal event. Conclusion Deterioration in renal function was observed 12 months after EVAR in patients receiving a stent-graft with suprarenal fixation, even though this did not seem to increase the likelihood of postoperative renal impairment. Furthermore, suprarenal fixation may be responsible for progressively significant proteinuria. Further studies are needed to determine the long-term impact of suprarenal fixation on renal function and investigate the potential risk of progressive renal disease in relation to type of fixation.


Case Reports in Medicine | 2011

Spinal cord ischemia after endovascular repair of infrarenal abdominal aortic aneurysm: a rare complication.

George Kouvelos; Nektario Papa; Christos Nassis; Nikolaos Xiropotamos; George Papadopoulos; Miltiadis Matsagkas

Neurologic deficit secondary to spinal cord ischemia after elective infrarenal, endovascular aneurysm repair (EVAR), consists a rare and rather disastrous complication. The etiology of such neurologic complication seems to be multifactorial, making this event unpredictable and foremost unpreventable. We report a case of paraparesis and bladder dysfunction that occurred immediately after the EVAR procedure. Prompt management by conservative or invasive methods seems to be important for the reversal of the neurologic deficit and the optimization of patients outcome.


Angiology | 2015

The effect of adding ezetimibe to rosuvastatin on renal function in patients undergoing elective vascular surgery.

George Kouvelos; Eleni Arnaoutoglou; Haralampos J. Milionis; Vaia D. Raikou; Nektario Papa; Miltiadis Matsagkas

We compared the effects of lipid lowering with rosuvastatin (RSV) monotherapy versus intensified treatment by combining RSV with ezetimibe (EZT) on kidney function in patients undergoing vascular surgery. Patients were randomly assigned to either 10 mg/d RSV (n = 136) or RSV 10 mg/d plus EZT 10 mg/d (RSV/EZT, n = 126). At 12 months, a similar decrease in estimated glomerular filtration rate (eGFR) was noted. Patients who achieved a low-density lipoprotein cholesterol (LDL-C) of <100 mg/dL had less eGFR decrease than those patients having an LDL-C limit of more than 100 mg/dL. There were no significant changes in the urinary total protein to creatinine ratio in either group. Significant microalbuminuria was evident in both the groups. Patients undergoing vascular surgery show deterioration in their renal function during the first year, despite statin therapy. Intensified lipid-lowering therapy by adding EZT does not appear to have any renoprotective effect.


Case Reports in Medicine | 2012

Limb-Shaking Transient Ischemic Attacks Successfully Treated with External Carotid Artery Stenting

George Kouvelos; Christos Nassis; Nektario Papa; George Papadopoulos; Miltiadis Matsagkas

The external carotid artery (ECA) is one of the most important extracranial-to-intracranial sources of collateral circulation, contributing significantly to the cerebral blood flow especially when perfusion through the internal carotid artery (ICA) is compromised. Most of the endovascular studies so far have been dedicated to ICA, with little focus on the ECA. Limb-shaking transient ischemic attacks (TIAs) are a relatively rare manifestation of carotid artery disease that may present with repetitive shaking movements of the affected limbs. We report a case of an 80-year-old male with bilateral internal and contralateral external carotid artery occlusion who developed limb-shaking TIAs as a result of significant stenosis of the right ECA. Percutaneous revascularization of the ECA was performed by angioplasty and stenting. At the follow-up 12 months later, the patient remained neurologically intact with complete resolution of his symptoms. Stenting of the ECA should be considered as a reasonable alternative to conventional open repair especially in patients with contralateral carotid stenosis, insufficient circle of Willis, and significant comorbidities.


Vascular | 2016

Platelet activation after endovascular repair of abdominal aortic aneurysm

Eleni Arnaoutoglou; George Kouvelos; Nektario Papa; Achilleas Karamoutsios; Vasilios Bouris; George Vartholomatos; Miltiadis Matsagkas

Aim To investigate the effect of endovascular aneurysm repair (EVAR) on platelet (PLT) function and reveal possible associated factors. Methods Fifty consecutive patients were included. PLT count and activation (CD62P-CD36), white blood cell (WBC) count, and high sensitivity C-reactive protein (hs-CRP) were measured preoperatively, at the first and third postoperative day. Results EVAR elicited a significant reduction in PLT count from baseline to first day after EVAR (p < 0.001), while no significant difference was noted between the first and third day. Furthermore, CD62P expression was markedly elevated at the first day after EVAR (median % positive PLTs from 13.7 at baseline to 22.1, p = 0.05), but returned to baseline levels by the third day. Maximum abdominal aortic aneurysm diameter was the only factor that significantly affected the CD62P values (p = 0.005). Postoperative CD36 values were significantly correlated with total aneurysm volume (p = 0.05) and were higher in endografts made from polyester (p = 0.01). There were no correlation between PLT activation and hs-CRP, WBC, maximum temperature, and 30-day morbidity. Conclusion EVAR has elucidated a significant reduction in PLT count and increase in PLT activation at the immediate postoperative period. The type of the endograft material and the aneurysm maximum diameter and volume appear to play an important role in PLT activation.


Journal of Vascular Surgery | 2013

Regarding "the impact of endograft type on inflammatory response after endovascular treatment of abdominal aortic aneurysm".

Eleni Arnaoutoglou; George Kouvelos; Nektario Papa; Miltiadis Matsagkas; Vasilios Koulouras; Haralampos J. Milionis

highlighting the utility of endovascular aneurysm repair in this frail group and the importance of careful patient selection for open repair in patients with any degree of COPD. Furthermore, Cox proportional hazards analysis not only confirmed oxygen dependence was associated with diminished 5-year survival, but also medically managed COPD, again emphasizing the ongoing challenge of selecting patients with COPD for aneurysm repair.


Anz Journal of Surgery | 2011

Spontaneous superficial femoral artery giant false aneurysm

George Kouvelos; Nektario Papa; Miltiadis Matsagkas

originating in the esophagus and hypopharynx. Ann. Thorac. Surg. 2006; 81: 393–6. 3. Fries MR, Galindo RL, Flint PW, Abraham SC. Giant fibrovascular polyp of the esophagus: a lesion causing upper airway obstruction and syncope. Arch. Pathol. Lab. Med. 2003; 127: 485–7. 4. Schuhmacher C, Becker K, Dittler H-J, Höfler H, Siewert JR, Stein HJ. Fibrovascular esophageal polyp as a diagnostic challenge. Dis. Esophagus 2000; 13: 324–7.

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